Mid-Term rents do cause a little complication...but that's what DSCR loans are for.   

not mortgage notes but tax liens those suckers are complicated .

Many people seem to complicate valuation issues more than needed, a strait forward way of looking at it is simply asking, "Would a buyer pay more for ...?"

Will it be very complicated to do a 1031 Exchange for my portion (provided that we relinquish the property and the sibling just receives the cash for her portion)?  

Tried a few but they are far from reliable...in a sense that if I am not on site things go sideways, or even no activity and completely missing for days. 

From personal experience, MLS deals are much less lucrative given their higher price points (typically).With respect to financing, you can talk to any of the hard money lenders on this site for different financing programs they offer (some are tighter with someone who has not yet executed a flip), you can take equity out on existing properties you have, you can use private loan from a friend or relative.

If the software is not simplifying your life or making you more accurate, you shouldn't use it.Software does have extremely helpful features like online payments, marketing syndication (click a button and your property is advertised on multiple sites), electronic document review/signing, maintenance tracking, and owner reports.

To qualify, an investment club:must not make, nor propose to make, a public offering of its securities; andmust not have more than 100 members.A public web site or other public communication that could be viewed as suggesting that a club is looking for new members might be considered a public offering.

Read this book - https://www.amazon.com/Every-Landlords-Property-Protection-Guide/dp/1413307000 - before getting into more complicated and expensive measures of protection.

You can also set up a direct booking site via iGMS.